This invention relates generally to the art of producing an inorganic sulfide, and more specifically to an improved process and apparatus for producing calcium sulfide and the calcium sulfide produced by the process.
A variety of laboratory processes exist for producing calcium sulfide. U.S. Pat. No. 4,348,299 discloses a laboratory process for producing calcium sulfide which involves heating a mixture of an oxidic material, such as carbonate, oxide, or an oxalate of calcium, with a reactive sulfurizing flux in a covered crucible in air at temperatures between 800xc2x0 and 1200xc2x0 C. for a time between 0.2 and 72 hours. U.S. Pat. No. 4,629,509 involves the addition of dry lime and an aqueous solution of an inorganic salt supplying sulfide (the combination resulting in calcium sulfide) to a solid residue in order to immobilize the residue.
Although the prior art devices may be suitable for their intended purposes, there is much room for improvement in the art of producing calcium sulfide.
It is therefore an object of this invention to provide an improved process and apparatus for producing calcium sulfide.
It is another object of this invention to provide calcium sulfide produced by the improved process and apparatus according to this invention.
It is another object of this invention to provide an improved process and apparatus that produces calcium sulfide economically.
It is yet another object of this invention to provide an improved process and apparatus that produces calcium sulfide in commercial quantities.
It is yet another object of this invention to provide an improved process and apparatus for producing calcium sulfide that can be set up and operated without difficulty.
These and other objects of the invention are achieved by a container housing at least one drum, the drum(s) having a substantially horizontal longitudinal center axis, wherein the drum(s) contain at least one screw conveyor substantially therein, the screw conveyor(s) being generally parallel to the horizontal center axis, an inlet passage for passing material into the container and drum(s), an outlet passage for passing material out of the drum(s) and container, and a heater for heating material within the drum(s); whereby reactants can be passed into the container and drum(s), wherein the reactants can be heated up within the drum(s) thereby substantially initiating a chemical reaction, the chemical reaction substantially converting reactants into products, wherein the reactants and products can be caused to move substantially horizontally in the drum(s) by the turning action of the screw conveyor(s), and wherein the products can be passed out of the drum(s) and container.